The invention relates to a cylinder head for an internal combustion engine with at least one intake port which generates a tumble flow in the combustion chamber, which channel is curved preferably in the direction of the tumble flow and comprises a wall region which is external relative to the tumble flow and an inner wall region, with a valve seat ring being arranged in the region of the opening of the intake port into the combustion chamber.
Cylinder heads with intake ports producing a tumble flow are known from U.S. Pat. No. 5,640,941 A, U.S. Pat. No. 5,165,374 A, U.S. Pat. No. 5,359,972 A or GB 2 165 886 A. Especially in the partial load region it is possible to favorably influence the progress of the combustion by the tumble flow and thus the fuel consumption and emission formation, with the highest possible tumble flow being desirable.
The amount of the tumble flow is relevantly determined by the position of the point of intersection of the central line of the intake port with the central line of the valve seat ring. The closer the point of intersection lies to the combustion chamber, the stronger the tumble flow. A strong inclination of the intake port relative to the central line of the valve seat ring allows for a strong tumble movement in the combustion chamber. A strong inclination of the central line of the flow of the intake port relative to the axis of the valve seat ring leads to the disadvantage however that the flow cross section of the intake port is strongly reduced, which has a disadvantageous effect especially in the full load range by a considerably reduced throughput. In designing the intake port it is therefore necessary to seek a compromise between high tumble flow in the partial load range and high throughput in the full load range.
From DE 1 295 274 B1 a gas exchange port of a cylinder head of an internal combustion engine is known in the opening region of which a valve seat ring is inserted which forms the inside curvature of the port wall at the core contact point. In one embodiment a wall region of the gas exchange port is formed in the region of the valve seat ring by an extension of the cylinder head within the valve seat ring. The valve seat ring is enclosed at least three sides directly by cylinder head material. This leads to multiple pressings and high mechanical stresses in this region.